Answer:Hydrostatic
Explanation: I think this is the answer, not sure. Sorry
Answer:
mass of box 1 = 2.20 kg
mass of box 2 = 5.93 kg
Explanation:
Let the mass of box 1 and box 2 is respectively
and 
so we will have
Force applied on box 1 then acceleration



Now we know that contact force between them in above case is given as



now we have

Efficiency = (energy that does the job) / (total energy used)
= (45 J) / (120J)
I think you can handle the division.